
/**

http://www.webtoolkit.info/javascript-base64.html

s1=Base64.encode("aa");
alert(s1);

s2=Base64.decode(s1);
alert(s2);


Javascript base64in Javascript


This javascript code is used to encode / decode
data using base64 (this encoding is designed to make
binary data survive transport through transport layers
that are not 8-bit clean). Script is fully compatible
with UTF-8 encoding. You can use base64 encoded data
as simple encryption mechanism.

If you plan using UTF-8 encoding in your project don’t forget
to set the page encoding to UTF-8 (Content-Type meta tag).
DEMO
Source code for webtoolkit.base64.js


*
* Base64 encode / decode
* http://www.webtoolkit.info/
*
**/

var Base64 = {

 // private property
 _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

 // public method for encoding
 encode : function (input) {
 var output = "";
 var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
 var i = 0;

 input = Base64._utf8_encode(input);

 while (i < input.length) {

 chr1 = input.charCodeAt(i++);
 chr2 = input.charCodeAt(i++);
 chr3 = input.charCodeAt(i++);

 enc1 = chr1 >> 2;
 enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
 enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
 enc4 = chr3 & 63;

 if (isNaN(chr2)) {
 enc3 = enc4 = 64;
 } else if (isNaN(chr3)) {
 enc4 = 64;
 }

 output = output +
 this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
 this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);

 }

 return output;
 },

 // public method for decoding
 decode : function (input) {
 var output = "";
 var chr1, chr2, chr3;
 var enc1, enc2, enc3, enc4;
 var i = 0;

 input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

 while (i < input.length) {

 enc1 = this._keyStr.indexOf(input.charAt(i++));
 enc2 = this._keyStr.indexOf(input.charAt(i++));
 enc3 = this._keyStr.indexOf(input.charAt(i++));
 enc4 = this._keyStr.indexOf(input.charAt(i++));

 chr1 = (enc1 << 2) | (enc2 >> 4);
 chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
 chr3 = ((enc3 & 3) << 6) | enc4;

 output = output + String.fromCharCode(chr1);

 if (enc3 != 64) {
 output = output + String.fromCharCode(chr2);
 }
 if (enc4 != 64) {
 output = output + String.fromCharCode(chr3);
 }

 }

 output = Base64._utf8_decode(output);

 return output;

 },

 // private method for UTF-8 encoding
 _utf8_encode : function (string) {
 string = string.replace(/\r\n/g,"\n");
 var utftext = "";

 for (var n = 0; n < string.length; n++) {

 var c = string.charCodeAt(n);

 if (c < 128) {
 utftext += String.fromCharCode(c);
 }
 else if((c > 127) && (c < 2048)) {
 utftext += String.fromCharCode((c >> 6) | 192);
 utftext += String.fromCharCode((c & 63) | 128);
 }
 else {
 utftext += String.fromCharCode((c >> 12) | 224);
 utftext += String.fromCharCode(((c >> 6) & 63) | 128);
 utftext += String.fromCharCode((c & 63) | 128);
 }

 }

 return utftext;
 },

 // private method for UTF-8 decoding
 _utf8_decode : function (utftext) {
 var string = "";
 var i = 0;
 var c = c1 = c2 = 0;

 while ( i < utftext.length ) {

 c = utftext.charCodeAt(i);

 if (c < 128) {
 string += String.fromCharCode(c);
 i++;
 }
 else if((c > 191) && (c < 224)) {
 c2 = utftext.charCodeAt(i+1);
 string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
 i += 2;
 }
 else {
 c2 = utftext.charCodeAt(i+1);
 c3 = utftext.charCodeAt(i+2);
 string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
 i += 3;
 }

 }

 return string;
 }

}


/// test

test_base=function(){
 s1=Base64.encode("aacc");
 alert(s1);
 s2=Base64.decode(s1);
 alert(s2);
}
// test_base();

